10th Class Mathematics Areas Related to Circles Question Bank MCQs - Areas Related to Circles

  • question_answer
    If the perimeter of a semi-circular protractor is \[\text{56 cm},\] then its diameter is:

    A) \[\text{10 cm}\]

    B) \[\text{14 cm}\]  

    C) \[\text{12 cm}\]

    D) \[\text{16 cm}\]

    Correct Answer: B

    Solution :

    [b]    Perimeter \[=\frac{2\pi r}{2}+2r=\pi r+2r\]
    \[(\pi +2)r=36\]
    \[\left( \frac{36}{7} \right)-r=36\]
    \[r=7cm\]
    Hence, diameter \[=7\times 2=14\,cm\]


You need to login to perform this action.
You will be redirected in 3 sec spinner